Hello, First of all thank you for your good work and assistance. Core dump trace is attached and a snippet follows. Choosing Help->Search Documentation causes seg fault. The remaining help menu items work fine. Please see below. Thank you so much. John ------------------------------------------------------------------- huatiger@huatiger:debug$ coredumpctl debug PID: 23503 (python2.7) UID: 1000 (huatiger) GID: 1000 (huatiger) Signal: 11 (SEGV) Timestamp: Sat 2020-02-29 14:35:13 EST (1min 8s ago) Command Line: /opt/UCSF/Chimera64-1.14/bin/python2.7 /opt/UCSF/Chimera64-1.14/share/__main__.py --debug Executable: /opt/UCSF/Chimera64-1.14/bin/python2.7 ... Core was generated by `/opt/UCSF/Chimera64-1.14/bin/python2.7 /opt/UCSF/Chimera64-1.14/share/__main__.'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00007fe3a31c51f8 in uncompress2 () from /lib/x86_64-linux-gnu/libz.so.1 ---------------------------------------------------------------------------------------- huatiger@huatiger:Downloads$ cat /etc/os-release NAME="Ubuntu" VERSION="19.10 (Eoan Ermine)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 19.10" VERSION_ID="19.10" HOME_URL="https://www.ubuntu.com/" SUPPORT_URL="https://help.ubuntu.com/" BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/" PRIVACY_POLICY_URL=" https://www.ubuntu.com/legal/terms-and-policies/privacy-policy" VERSION_CODENAME=eoan UBUNTU_CODENAME=eoan huatiger@huatiger:Downloads$ uname -a Linux huatiger 5.3.0-40-generic #32-Ubu